something like this:
<pre>
-[[!missingparents pages="posts/* and !posts/*/*" generate="""[[template id=year text="$page"]]"""]]
-[[!missingparents pages="posts/*/* and !posts/*/*/*" generate="""[[template id=month text="$page"]]"""]]
-[[!missingparents pages="posts/*/*/* and !posts/*/*/*/*" generate="""[[template id=day text="$page"]]"""]]
+[[!missingparents pages="posts/* and !posts/*/*" generate="""[[!template id=year text="$page"]]"""]]
+[[!missingparents pages="posts/*/* and !posts/*/*/*" generate="""[[!template id=month text="$page"]]"""]]
+[[!missingparents pages="posts/*/*/* and !posts/*/*/*/*" generate="""[[!template id=day text="$page"]]"""]]
</pre>
And it scans the whole wiki for pages that match the pagespecs but are missing